Reprising the role from the Arkham Origins video games and the Batman Unlimited home video/online short series for kids.
Also reprising the role from video games, though she's never played Catwoman in a non-game production.
Also from video games, though she's played the role in some recent animated productions including Scooby-Doo & Batman: The Brave and the Bold. I'm generally a fan of Tara Strong's work, but I find her Harley rather grating.
Reprising Deathstroke from Young Justice, though it's his first time as Grodd.
His first time as Robin (is this Dick or Damien?), though he's been Red Robin (Tim Drake) in Batman Unlimited.
New to both roles, though he's Nightwing in Unlimited and of course was Batman Beyond.
That's Tom Kenny, who's previously done Penguin in The Batman, LEGO Batman video games, and Scooby-Doo & Batman: TB&TB.
That's Eric Bauza, who's new to Two-Face but has played supporting roles in Batman Unlimited and video games.
No one fucking cares how good you are at looking at Google or Wikipedia to see what someone has done.